With the increasing proliferation of digital TV and radio systems, data streams, comprising e.g. video data and/or audio data, are broadcasted more and more frequently. In addition to the actual video and/or audio content such data streams further comprise metadata which allows e.g. for receiver-side control of program loudness and dynamic range, as well as for the control of stereo downmix and other features.
In typical network scenarios, video frames and/or audio frames and their associated metadata are encoded at a broadcasting headend system. For this purpose various encoding schemes such as Dolby E, Dolby Digital, AAC, HE AAC, DTS or Dolby Pulse may be used. Some of these encoding schemes, notably Dolby Pulse, AAC and HE AAC, are particularly well suited for the transmission over various transmission media, such as radio (e.g. FM frequency band, DVB/T, ATSC), twisted copper (DSL), coaxial cables (e.g. CATV) or optical fibers. The receiver, e.g. a TV set, a radio receiver, a personal computer or a set-top box, has an appropriate decoder and provides the decoded media stream. In addition, the receiver usually provides control features which are signaled via the metadata accompanying the video and/or audio data.
Examples of coding/decoding schemes are specified in ISO/IEC 14496-3 (2005) “Information technology—Coding of audio-visual objects—Part 3: Audio” for MPEG-4 AAC and in ISO/IEC 13818-7 (2003) “Generic Coding of Moving Pictures and Associated Audio information—Part 7: Advanced Audio Coding (AAC)” for MPEG-2 AAC which are incorporated herein by reference.
Several techniques for authentication and/or identification are known. Some rely on embedding authentication and/or identification data within coded multimedia data. These techniques are also known as watermarking and are specifically designed for copyright protection. A further technique for authentication and/or identification is the digital signature, where separate authentication data is provided along with data files such as Emails, and used at a decoder for authentication and identification purposes.
In order for the receiver of data streams to be able to identify the encoder of the data stream, it is desirable to provide authentication means along with the data stream. It may also be beneficial to verify the integrity of the data stream. In addition, it may be beneficial to ensure the correct configuration of the receiver with regards to the data stream that is to be played back or processed. Furthermore, it may be beneficial to allow for the implementation of value added services or special control functionalities for data streams which have been properly authenticated and/or verified. These and other issues are addressed in the present patent document.